84 delta, power seat works but makes chatering noise and front of seat wont go down

 

is there a question in there?

the power seat moves via a series of three motors and drive cables underneath the seat

the "plastic" (they're not plastic) housings that hold the motors and cables together start to fall apart after 30+ years

so the motors are no longer tight with the cables, or the cables aren't in tight with the seat geometry = noisy/inoperative seat movement

I don't know of a rebuild source for these...